Found in a 90s Radio Electronics, this circuit uses an AD590 or AD592 for remote temperature transmission. The circuit produces a voltage of 1 mV for each degree centigrade.
This circuit was found in an 80s documentation. The integrated circuit used is from that time,...
Texas Instruments has downloadable documentation on designing digital isolators. The Digital...
A low frequency divider can be made using common unijunction transistors as shown by the figure...